Question

我们正在为我们的学校制作游戏，这很简单，但是，我们无法弄清楚如何让它触发下一个级别。目前，我们有一个按钮设置，用于在完成关卡时加载新页面，但显然，使用此方法很容易作弊。我们想知道当红点（字符）到达顶部框时我们如何才能这样做，下一级将加载。我将发布第一级作为参考。

   <html>
<head>
<style>
            canvas, img {
            display:block; margin:1em auto; border:1px solid black;
            }
            canvas { 
            background:url(Clouds.png);
            }
        </style>
</head>
<body>
<canvas id="canvas" style="border:1px solid #000"></canvas>
<script>
    (function () {
    var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;
    window.requestAnimationFrame = requestAnimationFrame;
})();

var canvas = document.getElementById("canvas"),
    ctx = canvas.getContext("2d"),
    width = 500,
    height = 200,
    player = {
        x: width / 2,
        y: height - 15,
        width: 5,
        height: 5,
        speed: 3,
        velX: 0,
        velY: 0,
        jumping: false,
        grounded: false
    },
    keys = [],
    friction = 0.8,
    gravity = 0.3;

var boxes = [];

// dimensions
boxes.push({
    x: 0,
    y: 0,
    width: 10,
    height: height
});
boxes.push({
    x: 0,
    y: height - 2,
    width: width,
    height: 50
});
boxes.push({
    x: width - 10,
    y: 0,
    width: 50,
    height: height
});

boxes.push({
    x: 120,
    y: 10,
    width: 80,
    height: 80
});
boxes.push({
    x: 170,
    y: 50,
    width: 80,
    height: 80
});
boxes.push({
    x: 220,
    y: 100,
    width: 80,
    height: 80
});
boxes.push({
    x: 270,
    y: 150,
    width: 40,
    height: 40
});

canvas.width = width;
canvas.height = height;

function update() {
    // check keys
    if (keys[38] || keys[32] || keys[87]) {
        // up arrow or space
        if (!player.jumping && player.grounded) {
            player.jumping = true;
            player.grounded = false;
            player.velY = -player.speed * 2;
        }
    }
    if (keys[39] || keys[68]) {
        // right arrow
        if (player.velX < player.speed) {
            player.velX++;
        }
    }
    if (keys[37] || keys[65]) {
        // left arrow
        if (player.velX > -player.speed) {
            player.velX--;
        }
    }

    player.velX *= friction;
    player.velY += gravity;

    ctx.clearRect(0, 0, width, height);
    ctx.fillStyle = "black";
    ctx.beginPath();

    player.grounded = false;
    for (var i = 0; i < boxes.length; i++) {
        ctx.rect(boxes[i].x, boxes[i].y, boxes[i].width, boxes[i].height);

        var dir = colCheck(player, boxes[i]);

        if (dir === "l" || dir === "r") {
            player.velX = 0;
            player.jumping = false;
        } else if (dir === "b") {
            player.grounded = true;
            player.jumping = false;
        } else if (dir === "t") {
            player.velY *= -1;
        }

    }

    if(player.grounded){
         player.velY = 0;
    }

    player.x += player.velX;
    player.y += player.velY;

    ctx.fill();
    ctx.fillStyle = "red";
    ctx.fillRect(player.x, player.y, player.width, player.height);

    requestAnimationFrame(update);
}

function colCheck(shapeA, shapeB) {
    // get the vectors to check against
    var vX = (shapeA.x + (shapeA.width / 2)) - (shapeB.x + (shapeB.width / 2)),
        vY = (shapeA.y + (shapeA.height / 2)) - (shapeB.y + (shapeB.height / 2)),
        // add the half widths and half heights of the objects
        hWidths = (shapeA.width / 2) + (shapeB.width / 2),
        hHeights = (shapeA.height / 2) + (shapeB.height / 2),
        colDir = null;

    // if the x and y vector are less than the half width or half height, they we must be inside the object, causing a collision
    if (Math.abs(vX) < hWidths && Math.abs(vY) < hHeights) {
        // figures out on which side we are colliding (top, bottom, left, or right)
        var oX = hWidths - Math.abs(vX),
            oY = hHeights - Math.abs(vY);
        if (oX >= oY) {
            if (vY > 0) {
                colDir = "t";
                shapeA.y += oY;
            } else {
                colDir = "b";
                shapeA.y -= oY;
            }
        } else {
            if (vX > 0) {
                colDir = "l";
                shapeA.x += oX;
            } else {
                colDir = "r";
                shapeA.x -= oX;
            }
        }
    }
    return colDir;
}

document.body.addEventListener("keydown", function (e) {
    keys[e.keyCode] = true;
});

document.body.addEventListener("keyup", function (e) {
    keys[e.keyCode] = false;
});


window.addEventListener("load", function () {
    update();
});
</script>
<br>
<center>
<input type="button" name="next" value="Click me when finished! No cheating! ;)" onclick="location.href='level2.html';">
</center>
<center>
<input type="button" name="restart" value="Restart" onclick="location.href='javagame.html';">
</center>
</body>
</html>

Answer 1

在您的更新功能中，您可以添加逻辑，检查玩家是否处于与完成条件匹配的位置。然后在条件集location.href ='level2.html';

我假设条件是使用colCheck函数将播放器和顶部框作为参数并查找特定的返回值，这可以是您完成的练习。移动到下一级别的常规代码如下所示：

if(playerReachedFinish()) {
  location.href = 'level2.html';
}

在我们的javascript游戏中触发下一个级别？

1 个答案: